Declared In

start:

Parameters

completionBlock

Called when the operation is finished.

On success error will be nil and messages will be an array of MCOIMAPMessage.
vanishedMessages will contain the messages removed on the server if the server supports QRESYNC and if it was a sync request

On failure, error will be set with MCOErrorDomain as domain and an
error code available in MCOConstants.h, messages and vanishedMessages will be nil

If you are not supporting QRESYNC you can safely ignore vanishedMessages.